Hardcore Hornets Can Drink Alcohol All Week Without Getting Wasted

Consuming low levels of alcohol is actually pretty normal in the animal world. In the case of oriental hornets (Vespa orientalis), it’s the result of a delicious diet of not just other insects and carrion, but ripe fruits and nectar. The sugars in the latter two end up fermenting, producing ethanol.

For many species – even those well-adapted to ethanol consumption – consume anything above 4 percent ethanol concentration and things can start to go downhill, with an increased risk of negative health effects and death. 

Oriental hornets, however, can handle concentrations of ethanol as high as 80 percent without any changes to their behavior or survival – even when that’s all they consumed every single day for a week, a team of researchers from Tel Aviv University discovered.

The team collected male hornets from around the university grounds and placed them in boxes for a week with water and nothing to eat but a sugar solution with an ethanol concentration ranging from 0 to 80 percent. Across a series of experiments, they then monitored the hornets for their behavior, such as whether they built anything when materials like soil and paper were provided, and how long they lived.

Regardless of the concentration of ethanol the hornets were given, the researchers found that it had no effect on the insects’ behavior or mortality. In other words, an oriental hornet could drink any other animal under the table.

“In the beginning, we did the experiment only with 20 per cent [ethanol] and we were already amazed,” study author Eran Levin told New Scientist, adding that the 80 percent figure was “even harder to believe”.

Exactly how the hornets are able to consume such high concentrations of alcohol without any side effects comes down to their genetics, the authors explain in the study.

“This remarkable ethanol tolerance results from their high rates of ethanol metabolism, most likely enabled by their multiple copies of the alcohol dehydrogenase (NADP+) gene,” they write. Alcohol dehydrogenase is an enzyme that breaks down ethanol.

Although oriental hornets might come out of the animal drinking contest as the clear winners, that’s not to say there aren’t plenty of other species that don’t enjoy a good booze-up. Given the choice between water and alcohol, for example, hamsters are more likely to go for the hard stuff.

The study is published in PNAS.